Creating your own list is work that must be approached with diligence and care. You have many sources of list records of your own. People who call. People who write. People who send or respond to e-mail. Of course, as we have stated elsewhere in this site, your proven customers make your best list records.
The challenge is to enter the names from all these points of entry into a common, searchable, sortable database from which you can extract names, locations or other attributes to compile as lists. You must be prepared to maintain the list, determining if addresses, etc. are current and valid. The reward is a clean list of your very own qualified prospects and customers who you may reach with information about goods and services that you are fairly sure they already have some interest in obtaining. Plus, as the list grows, you can reap the financial rewards from renting it to other businesses.